Applying caulk so as to have effective sealing properties as well as a nice looking finish is a difficult endeavor, often thought of in layman's terms as more of an art than a science, not uncommonly a messy and unhappy job. A common procedure is to lay the bead from a caulk gun, and then finish it, often with only a wet finger. This procedure can leave uniformity at a loss, and, moreover, can be unpleasant, if not hazardous, as the composition may work upon or react with the flesh, and such things as splinters, nail heads and so forth can lacerate the finger moving over the bead or line of caulk. Those who can effectively finish caulk lines and make them look good consistently are expert workmen having much in the way of talent and experience.
Likewise, applying grout effectively to tile is not a job for an average layman. It, too, has pitfalls and dangers related to the materials employed and so forth.
It would be desirable to enable those of more common talent and less experience than such experts to effectively finish caulk, tile grout, and so forth and make it look good consistently. It would be desirable, too, to provide for an avoidance of such unpleasant if not hazardous things as mentioned above. It would be desirable to provide the art an alternative.